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Implementation of Accessibility-Based Evaluation for Transportation and Land-Use Planning

The concept of accessibility has made inroads into planning practice, largely at the system level. That is, accessibility is measured or modeled for current or future regional transportation and land-use scenarios for evaluation or broad policy guidance. Yet system-level scenarios cannot readily be applied to the project-by-project decision-making that characterizes the majority of land-use planning decisions. Accessibility evaluation of individual land-development projects differs from system-level analysis in essential ways and thus requires specialized tools. This article proposes an elasticity-based metric of accessibility that can enable project-level evaluation as an accessibility-based alternative to traffic-impact analysis. The metric is demonstrated for three land-development projects in Ann Arbor, Michigan, USA. The metric is shown to be sensitive to the location of development and capable of distinguishing among the analyzed projects in accessibility terms. Where mobility-based evaluation tends to rank peripheral development highly, the proposed accessibility metric appropriately rates central development as contributing the most to regional accessibility even after accounting for the traffic delay it engenders.